1. Technical Field The present disclosure relates to the fabrication and electronic packaging of miniature environmental sensors.
2. Description of the Related Art
With the advent of micro-mechanical systems, deployment of sensors and feedback control systems in smaller scale applications is made possible. For instance, many electronic devices now contain environmental sensors. In one example, electronic thermostats connected to climate control systems rely on temperature sensors to trigger activation of furnaces and air conditioners. In another example, electronic weather stations rely on internal temperature sensors, barometric pressure sensors, and humidity sensors.
Miniature sensors that are typically embedded on board mobile computing devices such as smart phones and tablet computers include, for example, magnetic field sensors used to determine orientation of a smart phone relative to the earth's magnetic field. Providing additional environmental micro-sensors within smart phones, tablet computers, and the like may encourage program developers to create applications that otherwise might not be possible. Such micro-sensors require very small dimensions to be suitable for use in mobile electronic devices. For example, the micro-sensors can be manufactured using 1-micron feature sizes on a semiconductor die size of about 1-3 square millimeters. In addition, such micro-sensors typically require signal processing circuitry that can be manufactured as application-specific integrated circuits (ASICs) having feature sizes in the range of about 10-100 nm.